Drill bit



1 644,142 1927' c. w. METZGER ET AL DRILL BIT Filed Dec. 20, 1926 ZSheets-S'nee'c l INV NTOR.

144% 7w y W {v6 ATTORNEYS] Oct. 4, 1927.

C. W. METZGER ET AL DRILL BIT Filed Dec. 20. 1926 2 Sheets-Sheet 2 INVENTORJ W 2 %T ORNEY Patented Get. 4, 1927,

NITE STATES PATENT OFFICE,

CLAUDENV. METZGER AND MARGIA MANNING, 0F HOUSTON, TEXAS.

DRILL BIT.

Application filed December 20, 1926. Serial No. 155,846.

This invention, relates to new and useful improvements in a drill bit.

One object of the invention is to provide a bit of the character described having detachable cutting blades and novel means for securing said blades to a bit head.

With the above and other objects in view this invention has particular relation to certain novel features of construction, arrange ment of parts and use, an example of which is given in this specification and illustrated in the accompanying drawings, wherein:

Figure 1 shows a side elevation of the bit showing one of the blades detached.

Figure :2 shows an edge view thereof.

Figure 3 shows a side elevation of a bit with one blade detached and showing another method of securing the blades to the head.

Figure 4 showsan edge view thereof, and

Figure 5 shows a bottom end view.

Referring now more particularly to the drawings, wherein like numerals of reference designate similar parts in each of the figures the numeral 1 designates the bit head whose upper end has an outwardly threaded pin 2, said head being flattened on each side and the pin 2 being provided for the reception of the drill collar in the usual way. The lower end of the head is reduced on each side forming a central blade anchor 3 with the side shoulders 4, 4, above it.

In the form shown in Figures 1 and 2 the sides of the anchor 3 have the deep grooves or mortises 5, 5, which are outwardly flared as designated by dotted lines in Figure 2 and the lower end of this anchor 3 has the spaced keys 6, 6, which taper outwardly. The bit blades are indicated by the numerals 7, 7. The inner edges of these blades are formed to conform to the corresponding part of and fit against the sides of the head 1 with their upper ends abutting against the respective shoulders 4. The innerside of each blade is formed with a tenon as 8 designed to fit in the mortise 5 and is also formed with a transverse keyway 9 provided to receive the corresponding key 6 which fits therein. When the blades are assembled the respective blades are retained in assembled relation with the head by means of .suitable set screws 10, 10, which are screwed into the head and the heads of these screws, when the screws are screwed home, seat in the arcuate recesses, as 11, in the upper ends of the blades 7 retaining said blades in place.

In the form shown in Figures 3 to 5 inclusive the lower end of the anchor is provided with the spaced mortises 12 which are flared downwardly and the sides of the anchor 3 are provided with downwardly taperng keys 13 and the bit blades 14, in this instance, have the transverse tenons 15' and the vertical keyways 16 designed to lit into the mortises 12 and to receive the keys 13 respectively. In this instance also set screws 17 are provided which are screwed into the anchor 3 and whose heads seat in the arcuate recess 18 in the inner edges of the blades when the screws are screwed home to lock the blades in assembled relation with the head.

What we claim is:

-1. A drill bit including a head whose lower end is reduced forming a blade anchor, said anchor being formed with integral keys and mortises, detachable blades each formed with a tenon adapted to fit into the corresponding mortises, and a keyvlyay provided to receive the corresponding 2. A drill bit including a head whose lower end is reduced forming a blade anchor, said anchor being formed with integral keys and mortises, detachable blades each formed with a tenon adapted to fit into, the corresponding mortise and a keyway provided to receive the corresponding key, and means for locking the blades in assembled relation with the head.

3. A drill bit including a head whose I lower end is reduced forming an anchor and side shoulders, detachable blades carried thereby whose upper ends abut said shoulders said anchor and blades being formed, one with integral tenons and keyways and the other with mortises and keys, said tenons and keys being adapted to fit into the corresponding mortises and keyways respectively when the blades are assembled with the head.

4. A drill bit including a head whose lower end is reduced forming an anchor and side shoulders, detachable blades carried thereby whose upper ends abut said shoulders, said anchor and blades bein formed one with tenons and keyways an the other with mortises and keys, said tenons and keys being adapted to fit into the an I I 1,644,142

' in assembled relation with the head. 7

5. A drill'including a head whose lower end is reduced forming a blade anchor with an overhanging shoulder, a detachable blade having a lateral shoulder which abuts the lower end of the anchor, the inner edge of the blade also abutting said anchor, said abutting parts being formed with atenon and keyway in substantially right angular relation and with a mortise and key de signed to intermesh with said tenon and keyway when the blade is assembled with the head, the upper end ofthe blade abutting said shoulder when the parts are so assembled. I

6. A drill including a headwhose lower end is reduced forming a blade anchor with an overhanging shoulder, a detachable blade whose inner edge abuts said anchor, said blade having a lateral shoulder which abuts the lower end of the anchor, said abutting parts being formed, one with a flared tenon and the other with a correspondingly shaped mortise formed to receive said tenon, and being also formed, one with a key and the other with a keyway designedto receive said key, said tenon and mortise being disposed at substantially right angular relation with respect to said key and keyway and the upper end of the blade abutting said overhanging shoulder when the blade is assembled with the head 7 7. A drill including a head, whose lower end is reduced forming a blade anchor with an overhanging shoulder, a detachable blade adapted to abut one edge of said anchor and having a lateral shoulder adapted to 'abut the lower end of the anchor, said abutting parts having a, tenon and a mortise adapted to receive the tenon and also having a key and a keyway adapted to receive said. hey, said'key and keyway extending at substantially right angles to the tenon and mortise.

In testimony whereof we have signed our names to this specification.

CLAUDE w. METZGER. MARGIAMANNING. J 

